4-trifluoromethyl-2, 6-dinitroanilines



United States Patent 3,403,180 4-TRIFLUOROMETHYL-2,6-DINITROANILINEQQuentin F. Soper, Indianapolis, Ind., assignor to Eli Lilly and Company,Indianapolis, Ind., a corporation of Indiana No Drawing.Continuation-impart of application Ser. No. 485,060, Sept. 3, 1965,which is a continuation-in-part of application Ser. No. 314,510, Oct. 7,1963. This application Oct. 19, 1966, Ser. No. 587,699

6 Claims. (Cl. 260-577) ABSTRACT OF THE DISCLOSURE This inventionrelates to a group of novel substituted anilines, useful in eliminatinggerminating and seedling weed grasses and selected broadleaf weeds.

The novel compounds provided by this invention are represented by thefollowing formula:

OzN N01 Ra R4 wherein R is (I -C alkyl, allyl, or hydrogen; R is methyl,ethyl, n-propyl, n-butyl, iso-butyl or allyl when R, is either O C,alkyl or ally]; and R is 2-pentyl or 3-pentyl when R is hydrogen; thesum of the carbon atoms in the groups represented by R and R beinggreater than 3.

In the above formula, when R is C -C alkyl, it represents ethyl,n-propyl, n-butyl, iso-butyl and the like.

Cross references to related applications Detailed description of theinvention Illustrative compounds coming within the scope of the aboveformula include:

N-methyl-N-iso-butyl-4-trifluoromethyl-2,6-dinitroanilineN-ethyl-N-iso-butyl-4-trifluoromethyl-2,6-dinitroanilineN-n-butyl-N-n-propyl-4-trifiuoromethyl-2,6-dinitroanilineN-methyl-N-n-propyl-4-trifiuoromethyl-2,6-dinitroanilineN-methyl-N-allyl-4-trifluoromethyl-2,6-dinitroanilineN,N-di-n-butyl-4-trifluoromethyl-2,6-dinitroanilineN-allyl-N-ethyl-4-trifluoromethyl-Z,6-dinitroaniline The compounds ofthis invention are useful in that they selectively kill germinating andseedling weed grasses and germinating and seedling broadleaf weedswithout damaging crop plants at any stage of growth whether asgerminating, seedling, or mature plants. They can thus be Patented Sept.24, 1968 employed as herbicides pre-emergent with respect to both Weedsand crops. Because of their lack of post-emergent herbicidal elfect oncrops, however, they are particularly useful in that they can be appliedas pre-emergent weedicides to areas in which the crop plant is alreadygrowing; i.e., pre-emergent to the weeds, but post-emergent to thecrops.

Compounds represented by the above formulas have an unexpectedly greaterherbicidal activity against germinating and seedling weed grasses andagainst a variety of broadleaf weeds in any stage of growth than docompounds containing hydrogen or another substitutent in the paraposition of the aniline ring.

The compounds of this invention are employed as selective pre-emergentherbicides by applying them to areas infested with seedling orgerminating weed grasses or seedling or germinating broadleaf weedseither as a spray, made up by adding water to an emulsifiableconcentrate or wettabl powder, or as a solid dispersion, using a carriersuch as attapulgite clay granules, peat moss, fertilizer, vermiculite,or the like. The compounds are quite insoluble in water, and hence, forthe preparation of emulsions or wettable powders, the compounds arepreferably formulated with wetting agents.

Herbicidal formulations containing a compound represented by the aboveformulas as the active ingredient are useful in eliminating seedling orgerminating weed grasses and a variety of broadleaf weeds in earlystages of growth from such areas as gravel walks, shoulders of roads,fence rows, clay tennis courts, flower gardens, drainage ditches,woodland areas, and the like. The compounds can also be applied for thesame purpose to crop-growing areas either in-row before or at plantingtime or between rows of crops.

It is a considerable advantage of this invention that theN-substituted-4-trifluoromethyl2,6-dinitroanilines as defined above donot affect the growth of crop plants either in the seedling or maturestages of growth or the growth of established turfs at concentrationswhich virtually eliminate germinating and seedling grasses and manygerminating and seedling broadleaf weeds from areas infested therewith.Thus, compounds of this invention can be applied as pre-emergent'weedicides to areas in which crops are either in the preorpost-emergent stage of growth.

Among the crop plants which will tolerate concentrations of anN-substituted-4-trifluoromethyl-2,6-dinitroaniline sufficient to killgerminating and seedling grasses and broadleaf weeds are the following:cotton, soybeans, tobacco, tomatoes, collards, great northern beans,kidney beans, navy beans, cowpeas, safilower, transplant peppers,peanuts, snapbeans, cauliflower, watermelon, brussels sprouts, cabbage,kale, asparagus, vetch, white potatoes, lettuce, carrots, rutabaga, limabeans, green peas, alfalfa, lespedeza, cucumbers, muskmelons, parsnips,okra, broccoli, sunflowers, pumpkins, radishes, sweet potatoes,peppermint, flax, and related species.

Because of the highly specific action of the compounds of the presentinvention, they can also be used safely to treat fields containingestablished crop plants which belong to the grass family. They can thusbe applied to stands of mature monocotyledonous plants such as sweetcorn, field corn, barley, wheat, rye, Japanese millet, German millet,bluegrass, sorghum, and the like in order to eliminate germinating andseedling grasses and germinating and seedling broadleaf weeds therefrom.

As previously stated, formulations of the compositions of the presentinvention can be applied to a crop area for the desired purpose in avariety of ways; e.g., by hand or broadcast treatment, either at thetime of planting, or after the crop has passed the seedling stage ofgrowth, as a lay-by treatment. It is also possible to apply compositionsutilizing the compounds of this invention as preemergent herbicidesbetween rows of established plants which are themselves quitesusceptible to the herbicidal action of the compounds. The type oftreatment chosen depends upon cost and upon the type of damage to theplant to be expected from an overdose of the herbicide, as well as uponother factors. Whenever possible, the herbicide should be incorporatedinto the soil, since such soil incorporation greatly increases theefiectiveness and length of action of the herbicide.

Herbicidal compositions containing a compound coming within the scope ofthe above formulas as its active ingredient can be employed to eliminategrasses such as the following in the germinating or the seedling stageof growth from an area infested therewith: Undesirable grasses such asthe crabgrasses (Digitaria sanguinalis and Digitaria ischaemunz), greenand yellow foxtails (Setarz'a viridis and Setaria glauca), Johnson grass(Sorghum halepense), goosegrass (Eleusiue indicia), sandbur (Cenchruspauciflorus), witchgrass (Pancium capillare) and the like; as well asthe seedlings of desirable grasses such as oats (Avena sativa), Bermudagrass (Cynodon dactylo n), Kentucky bluegrass (Poa pratensis), bentgrass(Agrostz's tennis), fescues (Festuca sp.), orchard grass (Dactylisglomerata), red top (Agrostis alba), sorghum (Sorghum vulgare), Germanmillet (Setaria italica'), Japanese millet (Echinochloa crusgalli var.frumentacea) and the like. Among the broadleaf weeds which can beeliminated by an application to an area infested with weed seeds of acompound coming within the scope of the above formulas are includedparticularly members of the genus Amaranthus such as pigweed; the genusPolygonum such as smartweed; the genus Chenopodium such as lambsquarter;the genus Stellaria such as chickweed; the genus Mollugo such ascarpetweed; the genus Salsola such as Russian thistle; as well asmembers of the genera Kochia and Portulaca.

In addition to their use as herbicides in crop-growing areas, along roadsides and gravel walks, etc., the novel compounds of the presentinvention can be suitably formulated for use to eliminate germinatingand seedling weed grasses, particularly crabgrass and foxtail, fromestablished lawns containing desirable grasses such as bluegrass,zoysia, St. Augustine grass, bentgrass, fescue, and Bermuda grass. Aswith the monocotyledonous crop plants, the relatively greatsusceptibility of grasses in the germinating or seedling stages ofgrowth to the herbicidal effects of theN-substituted-4-trifluoromethyl-2,6-dinitroanilines permits the use ofthese compounds to eliminate weed grasses from areas where a desirablegrass is already established.

Herbicidal compositions containing an effective amount of a compound ofthis invention are applied to those areas wherein it is desired toeliminate seedling grass weeds and broadleaf plants at rates varyingfrom around 0.1 to lb. per acre, depending upon the nature of the areaitself, including such factors as the crop, the weeds or broadleafplants, their state of growth, the type of soil and its content oforganic mattersand, and clay, and the like. For example, large amountsof even the most active herbicidalN-substituted-4-trifluoromethyl-2,6-dinitroaniline can be applied todriveways, roadsides, etc., since there is no liklihood that an overdosemight harm desirable plants. In addition, many turfs, particularly thoseof tall fescue and Bermuda grass, are very resistant to highconcentrations of even the most active of the compounds of the presentinvention. In other situations, however, where an excess of the compoundwould deleteriously affect the growth of desirable plants, it isnecessary to choose an application rate for the herbicidal compoundwhich will not damage the seedling or mature crop plant or grass turfand to apply the compound at the particular chosen dosage. For most ofthe compounds and for most crop plants, there is a considerable safetyfactor present between that dosage which will virtually eliminateseedling weed grasses and that dosage which will do even minimal damageto the crop plants or established grasses present in the same area.

Extensive tests have shown that one of the compounds most active inkilling germinating and seedling weed grasses and broadleaf weeds is anN,N-di-n-propyl 4-trifiuoromethyl-2,6-dinitroaniline, to be referred tohereinafter by its generic name, trifiuralin. In the greenhouse,trifiuralin eliminates in excess of percent of seedling weed grasses andbroadleaf weeds, such as pigweed, in the seedling stage of growth atapplication rates of about 0.5 lb. per acre. There is, on the otherhand, no appreciable damage to established plants except crabgrass atapplication rates as high as 8 lb. per acre. In the field, triliuralincan, when applied at rates of 1 to 16 lb. per acre by spraying and atrates of from 0.25 to 5 lb. per acre by soil incorporation, successfullyinhibit the growth of weed grasses and broadleaf weeds in the seedlingor germinating stages of growth. The application rate depends on thetype of soil to be treated, sandy soils requiring less herbicide, andheavy clay soils, relatively more herbicide. At rates up to 8 lb. peracre, very few broadleaf plant species in mature stages of growth aredamaged by the application of trifiuralin.

Trifluralin has also been used for the selective preemergent control ofseedling grass weeds and selected broadleaf weeds in ornamental flowerbeds, around shrubs and trees, in rose gardens, and in ground covers. Itcan be applied at rates sufficiently high to control weed populationwithout damage to the established plants. Among the broadleaf weedswhich have been controlled under these conditions are the following:carpetweed, chickweed, lambs-quarter, pigweed, purslane, knotweed, andsmartweed. In such experiments, trifiuralin was applied at rates in therange of l to 5 pounds per acre. At the latter level, the amount oftrifluralin applied was greatly in excess of that needed for immediatecontrol of crabgrass in the particular area, but the added amountprovided full-season protection against seedling grasses in all soiltypes. There was no damage to a wide variety of ornamental shrubs,trees, bulbs, flowering plants, and ground cover at the givenapplication rates.

Trifluralin has also been extensively tested in the field for itsability to control. grass weeds in soybean fields. For this purpose, itwas applied as a liquid formulation at rates varying from 0.5 to 1.5lbs. per acre as pre-plant soil-incorporation treatment. When applied inthis way, trifiuralin eliminated from 9399+ percent of the grass weeds,from 56-96 percent of pigweed and smartweed, and from 38-78 percent ofragweed seeded to the area at the same time as the soybeans. No damageto the soybeans was seen. Essentially the same results were obtainedwhen trifiuralin was applied to the test area as a solid formulation(for example, a 2.5 percent formulation on diatomaceous earth). Inanother field trial, this time with trifluralin alone, incorporation ofthe compound into the soil at the time of planting of the soybeans,after application to the area by spraying at rates varying from 0.5 to 4lbs. per acre, gave 100 percent control of crabgrass in most test plotsat all application rates, and the same for pigweed. The control ofpurslane, another broadleaf weed, was in excess of percent on theaverage.

Seedling grasses and susceptible broadleaf weeds can also be controlledin cotton fields by the application thereto of trifluralin as apre-emergent herbicide at the following rates, applied either in-row orbroadcast, and incorporated into the soil; 0.5 lb. per acre on sand,0.75 lb. per acre on loam, and 1.0-1.5 lbs. per acre on silty clay loamor clay soil. In numerous field trials using trifluralin at therecommended rates of application, the control of grass Weeds varied from92-100 percent and the control of broadleaf weeds from 60-100 percentwithout any perceptible damage to the cotton crop. Trifluralin can alsobe applied post-emergent to cotton as a lay by treatment.

Another outstanding composition of the present invention is N nbutyl-N-ethyl-4-trifluoromethyl-2,6-dinitroaniline, which will bereferred to hereinafter by its generic name, benefin.

Benefin has been extensively employed as a pre-emergent herbicide inlawns throughout the different climatic areas of the United States. Whenapplied at the rate of 1.5 to 2.0 lbs. per acre as a dry, spreadableformulation on a vermiculite or fertilizer carrier, containing from 0.3to 2 percent active compound by weight, benefin was found to killcompletely the following germinating and seedling grasses: goosegrass,barnyard grass, large crabgrass,

smooth crabgrass, foxtail, and annual bluegrass. Benefin can be appliedto an established bluegrass lawn anytime in the spring, and when thusapplied, will kill germinating weed grass seeds or seedling grasses aslong as the compound persists in the upper soil layer in a herbicidalconcentration which is usually for the duration of the weed grassgrowing season.

The lack of toxicity of benefin for turfs was established by theapplication of the compound to Bermuda grass turfs and Kentuckybluegrass turfs at rates as high as 6 lbs. per acre under favorableweather conditions without producing any perceptible damage to the turf.Benefin has also been used effectively on other turfs, including zoysia,St. Augustine grass, and Merion bluegrass.

Benefin has also been used successfully for the control of seedlinggrasses and of broadleaf weeds in peanut fields. With soil incorporationof benefin to the area to be planted in peanuts, using a disc,rotovator, or powerdriven rotary hoe as the incorporation tool, theindicated rate of application is 0.75 lb. per acre on sandy or loamysoil and 0.75 to 1.5 lbs. per acre on silty clay or clay soil. At theserates of application, there was little or no damage to the peanutplants, while the control of grass seedlings and susceptible broadleafweeds varied from 99-100 percent and 90-100 percent, respectively.

In addition, benefin has been used successfully to control weeds intobacco plantings. The compound can be applied to the soil during thetransplanting of tobacco seedlings. The rates of application areessentially the same as those indicated above for peanuts.

A third compound, N-(3-pentyl)-4-trifiuoromethyl-2,6- dinitroaniline, isalso a very effective pre-emergent weedicide and will virtuallyeliminate seedling weed grasses from snapbean fields when applied at arate which is one-fourth or less than that of the application rate whichis toxic to snapbeans.

The compounds of the present invention can be formulated in a variety ofways for application of soil areas. Among the suitable formulations areincluded wettable powders, emulsifible concentrates, and solid powderyor granular preparations on selected carriers. The formulations can alsoinclude other herbicides (for killing mature grasses and dicotyledonousplants), insecticides, miticides, etc. Typical formulations are setforth below.

FORMULATION 1 Solid formulation on vermiculite Percent Trifluralin 0.292,4-dichlorophenoxyacetic acid, iso-octyl ester 1.42,4,S-trichlorophenoxyacetic acid, iso-octyl ester 0.67

Sufficient disodium methylarsonate hexahydrate dust was blended with thevermiculite to give a concentration of 4 percent.

FORMULATION 2 Solid formulation on fertilizer The following activeingredients were dissolved in an aromatic naphtha solvent and depositedupon a 4-12-4 fertilizer to give a dry spreadable formulation having thefollowing composition in percentage by weight:

Percent Trifluralin 0.184 Heptachlor and related compounds 0.125

N (3 pentyl) 4 trifiuoromethyl 2,6 dinitroaniline can replacetrifluralin in the above composition.

FORMULATION 3 Spreadable formulation on lawn-type fertilizer Thefollowing ingredients were dissolved in an aromatic naphtha solvent anddeposited on a 10-5-5 fertilizer to give a spreadable formulation havingthe following composition in percentage by weight:

Percent Trifluralin 0.092 Heptachlor and related compounds 0.59

In addition, sufiicient diphenylacetonitrile (another preemergentherbicide) was melted on the fertilizer to iv a final concentration of4.6 percent.

FORMULATION 4 Solution concentrate A solution concentrate was preparedcontaining the following active ingredients in percentages by weight:

Percent Trifluralin 1.54 Disodium methylarsonate hexahydrate 4.52,4-dichlorophenoxyacetic acid, iso-octyl ester 1.742,4,5-trichlorophenoxyacetic acid, iso-octyl ester 0.55

(A) Granular formulations Percent (l) Trifluralin l-5 Xylene solvent 1-3Emulsifier 3-4 Diatomaceous earth granules 88-95 (2) Benefin 1-5 Xylenesolvent 1-3 Emulsifier 3-4 Diatomaceous earth granules 88-95 (3)Trifluralin 5.0 Methylated naphthalene solvent 6.0 Attapulgite claygranules 89.0 (4) Trifluralin 1.0-2.0 Aromatic naphtha solvent 1.0-3.0No. 4 vermiculite 95.0-98.0 (5) Trifluralin 0.5 Aromatic naphtha solvent4.5 Granular diatomaceous earth 95.0 (6) Trifluralin 1.0-2.0 Aromaticnaphtha solvent 0.5-3.5 Corncob grit 94.5-98.5

(7) N-(3-pentyl)-4-trifluoromethyl-2,6-

dinitroaniline 1.0 Aromatic petroleum distillate 4.0 No. 4 vermiculite95.0

(8 N- 3-pentyl -4-trifiuoromethyl-2,6-

dinitroaniline 5.0 Aromatic'petroleum distillate 6.0 Diatomaceous earth89.0

(9) N- 3-pentyl -4-trifluoromethyl-2,6-

dinitroaniline 5.0 Aromatic petroleum distillate 4.0 Ethylene oxideadduct of nonylphenol 7.5 Granular clay 83.5

Percent N-(3-pentyl) -4-trifluoromethyl-2,6-

dinitroaniline 2.0 Aromatic petroleum distillate 3.5 Corn cob grit 94.5

(B) Liquid concentrate formulations 1) Trifluralin 35.0-37.5 Emulsifier2.5-5.0 Xylene solvent 57.0-61.5 (2) Trifluralin 46.0-49.0 Emulsifier3.5-5.0 Xylene solvent 46.0-49.5 (3) Trifiuralin (60-69% solution) inaromatic naphtha solvent 69.0-75.0 Emulsifier 7.0 Xylene solvent18.5-25.0 (4) Benefin 19.0-22.0 Emulsifier 2-6 Xylene solvent 72-79 (5N-(3-pentyl -4-trifiuoromethyl-2,6-

dinitroaniline 46-49 Emulsifier 5 Xylene range solvent 46-49 (6)N-(3-pentyl)-4-trifiuoromethyl-2,6-

dinitroaniline 43-46 Emulsifier 7 Heavy aromatic naphtha 47-50 (C) Waterdispersible dry powder (1) N-(3-pentyl) -4-trifiuoromethyl-2,6-

dinitroaniline Ethylene oxide adduct of octylphenol 2 Lignin sulfonate 2Hydrated silica 76 In the above liquid formulations, the emulsifier canbe any suitable anionic or non-ionic surfactant or a mixture of thesetwo types of surfactants. Typical of the latter are blends containingthree parts of the calcium salt of myristylbenzenesulfonic acid to onepart of the oleate ester of a polyoxyethylene glycol (M.W.=350) or sevenparts of the calcium salt of laurylphenolsulfonic acid to three parts ofmonoand di-resin acid esters of polyoxyethylene glycol (M.W.=500). Othernon-ionic surfactants which are commonly blended with the anionicsurfactants listed above include polyoxyethylene sorbitan monolaurate. Aparticularly useful emulsifier combination for use in the liquidformulation No. 3 above includes 2.1% of an alkylarylsulfonate and 4.9%of an anionic nonionic surfactant mixture containing a magnesium salt ofa cetylphenolsulfonic acid and a monoand di-resin acid ester of apolyoxyethylene glycol (M.W.=400). Other suitable emulsifiers willreadily suggest themselves to those skilled in the art.

The N-substituted-4-trifiuoromethyl-2,6-dinitroanilines provided by thisinvention are either low-melting, yellow, crystalline solids or heavy,orange-colored, viscous oils. They are readily prepared by heating4-triflu0romethyl- 2,6-dinitrochlorobenzene with a primary or secondaryamine in an inert solvent. For example, N,N-di-n-propyl-4-trifiuoromethyl-2,6-dinitroaniline is prepared by reacting4-trifiuoromethyl2,6-dinitrochlorobenzene with an excess ofdi-n-propylamine in a suitable nonreacting solvent such as benzene orethanol. Hydrogen chloride produced as a by-product in the reaction isimmediately picked up by the excess di-n-propylamine present, thusforming di-npropylamine hydrochloride. If a nonpolar organic solventsuch as benzene is used in which the hydrochloride salt is insoluble,the salt can be separated by filtration and the desiredN,N-di-n-propyl-4-trifluoromethyl-2,6-dinitroaniline recovered byevaporation of the filtrate. If a polar organic solvent such as ethanolis used in which the hydrochloride salt is soluble, the reaction mixtureis evap orated to dryness and the residue treated with a mixture ofwater and ether. The hydrochloride salt dissolves in the water and theN,N-di-n-propyl-4-trifiuoromethyl-Z,6-

dinitroaniline is extracted into the ether layer and recovered byevaporation of the ether.

The following examples further exemplify the compounds of this inventionand methods of preparing them:

EXAMPLE Fifty grams of 4-chloro-3,S-dinitrobenzoic acid were reactedwith 50 g. of sulfur tetrafluoride in an autoclave at 120 C. for 7 hoursto form 4-trifluoromethyl-2,6- dinitrochlorobenzene. Evaporation of thereaction mixture to dryness left a solid residue comprising4-trifiuoromethyl-2,6-dinitrochlorobenzene, which was purified byrecrystallization from a hexane-benzene solvent mixture. Crystalline4-trifluoro-methyl-2,6-dinitrochlorobenzene thus prepared melted atabout 53-57 C.

Analysis.Calc.: N, 10.35. Found: N, 9.90.

Eight and one-tenth grams of 4-trifiuoromethyl-2,6-dinitrochlorobenzenewere mixed with 10 ml. of di-n-propylamine, and the reaction mixture washeated at about 100 C. for about 2 hours. The reaction mixture wasdiluted with ether and was filtered to remove di-n-propylaminehydrochloride formed as a by-product in the reaction. The filtrate waswashed with dilute hydrochloric acid and then was evaporated to drynessin vacuo. The residue, containingN,N-di-n-propyl-4-t1ifiuoromethyl-2,6-dinitroaniline, was recrystallizedfrom hexane and melted at about 41-43 C.

Analysis.Calc.: C, 46.57; H, 4.81; N, 12.53. Found: C, 46.56; H, 4.9; N,12.62.

The following compounds were prepared by the above procedure bysubstituting the appropriate amine for di-npropylamine:

N,N-diethyl 4 trifiuoromethyl 2,6 dinitroaniline, M.P.=93.5 C.

Analysis.Calc.: N, 13.68. Found: N, 13.77.

N,N-di-iso-butyl-4-trifiuoromethyl 2,6 dinitroaniline, M.P.=71-72 C.

Analysis.Calc.: N, 11.57. Found: N, 11.36.

N-methyl-N-n-butyl 4 trifiuoromethyl 2,6 dinitroaniline, M.P.=49-51 C.

Analysis.Calc.: N, 13.08. Found: N, 13.22.

N-ethyl-N-n-butyl 4 trifiuoromethyl 2,6 dinitroaniline, M.P.=65-66.5 C.

Analysis.Calc.: N, 12.53. Found: N, 12.76.

N-ethyl-N-n-propyl 4 trifiuoromethyl 2,6 dinitroaniline, M.P.=8991 C.

Analysis.Calc.: N, 13.08. Found: N, 13.35.

N,N-diallyl 4 trifluoromethyl 2,6 dinitroaniline, M.P.=61-62 C.

Analysis.Calc.: N, 12.69. Found: N, 12.42.

N-(3-pentyl) 4 trifluoromethyl 2,6 dinitroaniline, M.P.=71-73 C.

Analysis-Cale: N, 13.08. Found: N, 12.79.

N-(Z-pentyl) 4 trifiuoromethyl 2,6 dinitroaniline, M.P.=32-34 C.

Analysis-Cale: N, 13.08. Found: N, 12.80.

I claim:

1. A compound represented by the following formula:

wherein R is C -C alkyl, allyl, or hydrogen; R is methyl, ethyl,n-propyl, n-butyl, iso-butyl or allyl when R is either C -C alkyl orallyl; and R is 2-pentyl or 3-pentyl when R is hydrogen; the sum of thecarbon atoms in the groups represented by R, and R being greater than 3.

4. A compound according to claim 1 wherein R is 5 n-butyl and R isethyl.

5. A compound according to claim 1 wherein R is n-butyl and R isn-propyl.

6. A compound according to claim 1 wherein R is hydrogen and R is3-pentyl.

References Cited UNITED STATES PATENTS 2,212,825 8/1940 Daudt et a1.260-577 XR 3,257,190 6/1966 Soper 260'577 XR 3,332,769 7/1967 Soper260-577 XR CHARLES B. PARKER, Primary Examiner.

P. C. IVES, Assistant Examiner.

